In the simplest form, Functional foods are foods or food ingredients that provide health benefits beyond the basic nutrition, as a result of physiologically active food components. A functional food boosts optimal health, advances the immune system and can help prevent chronic diseases.
Dear readers, my name is Chiamaka Belsonia, the early stage researcher-9 of the SULTAN project. I’m currently running my research activities at Helmholtz-Zentrum Dresden Rossendorf (HZDR) and it’s focused on developing innovative bioleaching approaches that can be used to extract valuable and hazardous elements from sulfidic tailings. However, in my blogs, I won’t only be discussing my project, but will write also about food, health, nutrition and general wellbeing of humans. Perhaps, this is owed to the fact that food and nutrition is a very important topic to all human beings irrespective of our career fields; as well as the fact that I was a biochemist who majored in Nutritional Biochemistry during the course of my first university degree.
You’d probably be asking yourself “What are functional foods?” “Why is a Food called functional?” In the simplest form, Functional foods are foods or food ingredients that provide health benefits beyond the basic nutrition, as a result of physiologically active food components [1]. A functional food boosts optimal health, advances the immune system and can help prevent chronic diseases [2]. The first set of detailed researches dedicated to the concept of functional foods was carried out in Japan in the 1980s and funded by the Japanese government. This led to a defined systematic approach to assess the functionality of food. They established that in addition to exerting a physiological effect, a functional food must be in form of an ordinary food (not capsules or pills) and eaten as part of a normal diet [3].
A functional food can be categorized as [4];
- A common food with natural bioactive substances (e.g fruits, grain, nuts and vegetables)
- A food supplemented with bioactive substances (e.g probiotics)
- Derivative food ingredients which are added into traditional foods (e.g prebiotics)
I am sure many of us know a lot of foods to be healthy, however the knowledge of why and how these foods provide us with health benefits will make us appreciate these foods more and of course aid us in making greater food choices and leading a healthy lifestyle. Now let’s take a look at one of these plant-based functional foods and its numerous health benefits.
GINGER (Zingiber officinale)
Ginger is consumed worldwide as spice flavoring agent, medicine and food preservative. The health benefits of Ginger are inexhaustible; it is known for its immense phytotherapeutic properties. Using various analytical techniques, about 115 phytochemicals have been identified in various varieties of fresh and dried ginger [5], which could be responsible for its physiological effects. The gingerols and shogaols which are the main contents of fresh and dried ginger respectively, are the most popular of these ginger components and have been shown to have various pharmacological activities [6]. For example, the potential biological activities of 6-shogaol and 10-gingerol are illustrated in figures 1 and 2 respectively.
Figure 1: Potential bioactivities of 6-shogaol [21].
Figure 2: Potential bioactivities of 10-gingerol [22].
In the digestive system, Ginger is a potent stomachic because it can promote the appetite and aid digestion. Ginger helps relieve symptoms of gastrointestinal disorders such as cramps, pregnancy-related morning sickness, anorexia, motion sickness, nausea, constipation, dyspepsia, diarrhea, vomiting and colon spasms [7]. This is evident in the renowned Ayurvedic drug called trikatu, which is an effective drug for normal gastric function and has ginger as one of its main component [8].
Ginger has long been used for the treatment of various cardiovascular diseases due to its powerful blood pressure-lowering and diuretic effect. A research confirmed that ginger consumed at specific doses effectively lowered blood pressure in humans [9]. The mechanism for the blood pressure-lowering effect of ginger was discovered to be possible through the specific inhibition of the voltage-dependent Ca2 channels [10] which normally stimulates the contraction of the smooth muscle tissue in organs and arterial walls. Therefore reduced smooth muscle contraction resulted in relaxed arterial walls, leading to easy flow of blood and therefore, reduced blood pressure [11].
The anti-thrombotic activity of Ginger has also been studied which showed that Ginger could effectively prevent procedures (platelet aggregation and thromboxane-B2 (TXB2) production) that lead to thrombosis [12-13]. Thrombosis is the formation of blood clot in a blood vessel thereby preventing the normal flow of blood in the circulatory system. Another research showed that ginger could potentially reduce serum cholesterol, as well as serve as an effective anti-inflammatory agent by reducing serum prostaglandin-E2 [6] which play major roles in the generation of inflammatory response [14].
The anti-cancer activities of various forms of Ginger have also been investigated. A lot of studies have shown that ginger could be very effective in preventing and inhibiting cancer growth in various cancer types. It has been proposed that the anti-cancer activities of ginger and its components (mainly 6-gingerol, 6-shogaol and zerumbone) are effected via the stimulation of apoptosis, reduction of proliferation, and cell-cycle arrest [5]. The chain reactions that lead to these three mechanisms for the anticancer activities of 6-gingerol are shown in Figure 3 below.
Figure 3: The several signaling pathways involved in the anticancer mechanisms of 6-gingerol [23].
CDK: Cyclin-dependent kinase; PI3K: Phosphoinositide 3-kinase; Akt: Protein kinase B; mTOR: Mammalian target of rapamycin; AMPK: 5’adenosine monophosphate-activated protein kinase; Bax: Bcl-2-associated X protein; Bcl-2: B-cell lymphoma 2.
Other notable uses of ginger are reduction of cold and cough, helps eliminate nasal congestion and also ginger tea eases sore throat [15]. Ginger also helps to prevent obesity, regulates menstrual irregularities and dysmenorrheal and also acts as a food preservative [16-19]. Ginger may also have antidiabetic activity because it helped control blood-glucose levels in diabetic rats [20]. Research also suggests that ginger consumption is safe with very little side effects [5]. I could go on and on about the tremendous benefits of ginger but this platform would not contain all, so to find out more, please read the papers in the reference section below and also see the diagram below (figure 4) which summarizes the functionality of ginger as a food.
Figure 4: Bioactivities of ginger [23].
Ginger could be used either as a dry powder or as a fresh paste. Instead of a cup of coffee in the morning, why not have a cup of green or black tea complemented with blended fresh ginger? Are you very busy and you think you do not have time to peel and blend ginger each time you need to add it to your tea or meal? Well, there is good news for you, a litre of blended fresh ginger can be preserved in a refrigerator for up to one week or even more. So as you make plans for your meals everyday, also ask yourself what functional ingredient or food you can add to your meal that can give you a health benefit. In my next blogs, we will look at other interesting functional foods, so please stay tuned. In conclusion, I will end with the so-called Hippocrates (400 BC) quote, “Let thy food be thy medicine and thy medicine thy food”.
References
[1]. Hasler, C. M. (2002) Functional foods: benefits, concerns and challenges-a position paper from the American council on Science and health. J. Nutr. 132 (12), 3772–3781.
[2]. Bhat, Z. F., and Bhat, H. (2011) Milk and Diary Products as Functional Foods: A Review. Intl J. Diary Science 6: 1-12.
[3]. Howlett, J. (2008) Functional Foods from Science to Health and Claims. International Life Science Institute Europe, ISBN 9789078637110.
[4]. Al-Sheraji, S. H., Ismail, A., Manap, M. Y., Mustafa, S., Yusof, R. M., and Hassan, F. A. (2013) Prebiotics as functional foods: A review. J. Funct. Foods (4), 1542–1553.
[5]. Bode, A. M., and Dong, Z. (2011) The amazing and Mighty ginger – Herbal Medicine: Biomolecular and Clinical Aspects. Taylor and Francis Group, LLC.
[6]. Thomson, M., Al-Qattan, K. K., Al-Sawan, S. W., Alnaqeeb, M. A., Khan, I., and Ali, M. (2002) The use of ginger (Zingiber officinale Rosc.) as a potential anti-inflammatory and antithrombotic agent. Prostaglandins, Leukotrienes and Essential Fatty Acids 67 (6), 475-478.
[7]. Bhatt, N., Waly, M. I., Essa, M. M., and Ali, A. (2013) Ginger: A functional herb. In Food as Medicine (M.M. Essa and M.A. Memon, eds.) pp. 51–71, Nova Science Publishers, New York, NY.
[8]. https://www.ayurvedichealing.net/product/trikatu/
[9]. Ojulari, L. S., Olatubosun, O. T., Okesina, K. B., and Owoyele, B. V. (2014) The Effect of Zingiber Officinale (Ginger) Extract on Blood Pressure and Heart Rate in Healthy Humans. Journal of Dental and Medical Sciences 13 (10): 76-78.
[10]. Ghayur, M. N., and Gilani, A. H. (2005) Ginger Lowers Blood Pressure through Blockade of Voltage-Dependent Calcium Channels. J Cardiovasc Pharmacol 45 (1): 74-80.
[11]. Shaban, M. I., El-Gahsh, N. F. A., and El-sol, A. E. H. (2017) Ginger: It's Effect on Blood Pressure among Hypertensive Patients. Journal of Nursing and Health Science 6 (5): 79-86.
[12]. Srivastava, K. C., and Mustafa, T. (1989) Spices: antiplatelet activity and prostanoid metabolism. Prostaglandins Leukot Essent Fatty Acids 38 (4): 255-266.
[13]. Srivastava K. C. (1984) Effects of aqueous extracts of Onion, Garlic and Ginger on platelet aggregation and metabolism of arachidonic acid in the blood vascular system: in vitro study. Prostaglandins Leukot Med 13 (2): 227-235.
[14]. Ricciotti, E., and FitzGerald, G. A. (2011) Prostaglandins and Inflammation. Arterioscler Thromb Vasc Biol 31(5): 986–1000.
[15]. Sultana, S., Khan, A., Safhi, M. M., and Alhazmi, H. A. (2016) Cough Suppressant Herbal Drugs: A Review. International Journal of Pharmaceutical Science Invention 5 (5): 15-28.
[16]. Kim, S., Lee, M. S., Jung, S., Son, H. Y., Park, S., Kang, B., Kim, S. Y., Kim, I. H., Kim, C. T., and Kim, Y. (2018). Ginger Extract Ameliorates Obesity and Inflammation via Regulating MicroRNA-21/132 Expression and AMPK Activation in White Adipose Tissue. Nutrients, 10(11): 1567.
[17]. Wang, J., Li, D., Wang, P., Hu, X., and Chen, F. (2019) Ginger prevents obesity through regulation of energy metabolism and activation of browning in high-fat diet-induced obese mice. J Nutr Biochem 70: 105–115.
[18]. Daily, J. W., Zhang, X., Kim, D. S., and Park, S. (2015) Efficacy of Ginger for Alleviating the Symptoms of Primary Dysmenorrhea: A Systematic Review and Meta-analysis of Randomized Clinical Trials. Pain Medicine 16 (12): 2243–2255.
[19]. Ayanniran, A. I. (2014) Preservative activity of ethanolic extract of ginger in wara – a west african traditional soft (unripened) cheese. Journal of Food Technology Research 1 (1): 45-51.
[20]. Islam, M. S., and Choi, H. (2008) Comparative effects of dietary ginger (Zingiber officinale) and garlic (Allium sativum) investigated in a type 2 diabetes model of rats. J Med Food 11(1): 152–9.
[21]. Kou, X., Wang, X., Ji, R., Liu, L., Qiao, Y., Lou, Z., Ma, C., Li, S., Wang, H., and Ho, C. T. (2018) Occurrence, biological activity and metabolism of 6-shogaol. Food Funct. 9: 1310-1327.
[22]. Zhang, F., Thakur, K., Hu, F., Zhang, J. G., and Wei, Z. J. (2017) Cross-talk between 10-gingerol and its anti-cancerous potential: a recent update. Food Funct. 8: 2635-2649.
[23]. Mao, Q., Xu, X., Cao, S., Gan, R., Corke, H., Beta, T., and Li, H. (2019) Bioactive Compounds and Bioactivities of Ginger (Zingiber officinale Roscoe). Foods 8(6): 185.